Sensors can be classified based on power or energy supply
requirement of the sensors:

Active Sensor – Sensors that require power supply are called as
Active Sensors.like the LiDAR (Light detection and ranging),
photo-conductive cell.

Passive Sensor – Sensors that do not require power supply are
called as Passive Sensors

In the current and future
applications, sensors can be classified into groups as follows:

Accelerometers – These are based on
the Micro Electro Mechanical sensor technology. They are used for patient
monitoring which includes pace makers and vehicle dynamic systems.

Biosensors – These are based on the
electro-chemical technology. They are used for food testing, medical care
device, water testing, and biological warfare agent detection.

Image Sensors – They are used in
consumer electronics,traffic and security surveillance and PC imaging.

Motion Detectors – These are based on
the Ultrasonic and Radar Technology which is used in video games and
simulations light detection.

Conclusion : This technology was introduced to develop machines which can
substitute for humans. Robots are that kind of machines that can be used in any
situation or for any purposes. But today, many robots are generally used in
dangerous environments, manufacturing processes, or that jobs which are
dangerous for humans. Robots can be in many forms. But some are made like a
human. These robots are called humanoid robots. These Robots can do exactly what the humans do.